1. Field of the Present Invention
The present invention relates to a display device using a light-emitting element.
2. Description of the Related Art
In recent years, development of an electroluminescence (Electro Luminescence) display device in which thin film transistors (hereafter also referred to as “TFTs”) are integrated over a substrate has progressed. In such a display device, thin film transistors are manufactured over a substrate by using thin-film formation technology and a light-emitting element (electroluminescence (hereinafter also referred to as “EL”) element) is formed as a display element over various circuits including the thin film transistors.
In pixels of a display device using light-emitting elements, respective amounts of current flowing into the light-emitting elements vary depending on variations of electrical characteristics such as each threshold voltage of TFTs for forming the pixels, so that there is a problem of variation in luminance of the light-emitting elements. A structure in which such variation in threshold voltage of TFTs is compensated using a capacitor has been disclosed (e.g., see Patent Document 1: U.S. Pat. No. 6,229,506).